Next we may speak of steam and hot-water heating. So far as a change of air and the ventilation of the room are concerned, heating by direct radiation, that is, by radiators placed in the room, is no better than stove heating. It may be that the air is not so severely parched by the extreme heat, also the escape of steam may contribute somewhat to the moisture of the air; but the escape of steam is not agreeable, and is not allowed to exist to any great extent;—its odor is not always pleasant. Certainly the addition of moisture to the air by this means would be a mere makeshift and unsatisfactory.
Hot-water coils act the same as steam radiators in that they heat the same air over and over again, and are no better than stoves, so far as the provision for fresh air, at proper temperature and humidity, is concerned.
A steam or hot-water apparatus, with indirect radiation, is superior to furnace heat as ordinarily provided. The means of supplying moisture to an indirect steam apparatus, as ordinarily constructed, are not convenient. There is a radiator for each hot-air connection above, that is, a radiator for each register, with a distinct and direct supply of outer air thereto. Sometimes there are two registers connecting with a single radiator. But under any circumstances the radiators are somewhat separated, having steam or water connection with the boiler at the proper point. Steam apparatus for public buildings has been constructed where the radiators have been bunched, that is, put into a single chamber, the air passing through the chamber containing the radiators, where it is heated to the proper temperature, and the moisture afterwards supplied before it enters the room. Where this arrangement is used, there must be conductors, tin or otherwise, from the chamber to the register, as in the case of a furnace. Again, it will be found that the supply of air will not be uniform through all of the openings; for instance, the register that is farthest removed from the warm-air chamber may fail to act. In this event, auxiliary radiators may be placed under that register, and the operation of the heating apparatus greatly facilitated thereby. This plan is superior to a furnace, and can be applied to hot-water or steam apparatus in dwellings. The reason that it is superior to a furnace is that the supply of heat is more uniform. It does not require the constant firing or attention that is necessary in the case of a hot-air furnace. It may be known that the temperature does not change with the pressure of steam or in the same proportion.
There are inexpensive automatic arrangements in connection with furnaces and steam apparatus, which control the dampers and keep the steam pressure measurably uniform, as long as there is fuel of sufficient quantity in the fire-pot. The hot-water apparatus is more uniform in its operation than steam, and for that reason more satisfactory.
A furnace plant is the most inexpensive apparatus that may be used for general heating; the steam apparatus is next higher as to first cost, though no more expensive in amount of fuel used. The hot-water apparatus costs more than steam, and is somewhat more economical in the cost of maintenance. It is probable that a house of moderate size can be warmed all over at a less cost, as far as fuel is concerned, by a furnace or a steam or hot-water heating apparatus than by stoves and grates. However, grates are generally used in addition to these for the purpose of comfort and appearance, and for ventilating. Under such circumstances, they consume very little fuel.
CHAPTER XII.
HEATING DEVICES AS WE FIND THEM.—FURNACE ESTIMATES.—COMBINATION HOT AIR AND HOT WATER.—DISH-WARMING ARRANGEMENTS.—HOW TO GET A GOOD HEATING APPARATUS.
For the present, people who build must take things as they find them, and use heating and ventilating apparatus as regularly manufactured. Experiments are uncertain. The theory of the proper heating and ventilating of a house as set forth in previous chapter is correct. The fulfilment of the ideas in dwelling-house heating remains to be practically worked out. It is not the business of the architect, or the housewife, or the owner of the house, to work out these mechanical details. It will be done in time by competent mechanical experts.